SpaceX Successfully Launches NRO Satellite
SpaceX Successfully Launches U.S. NRO Spy Satellite (With video)
“SpaceX launched a spy satellite for the U.S. National Reconnaissance Office (NRO) early this morning after a one day delay. The launch appears to have placed the secret payload into a low earth orbit. SpaceX also successfully landed the first stage of the Falcon 9 rocket.”
Marc’s note: The video portion showing the return of the first stage is quite spectacular, providing views we haven’t seen in this detail before. It starts around the 24 minute mark.
Yeah, that’s how you do that. I think that the footage of the turn-around, entry, descent and landing promises to become one of those classic videos that become part of history. I expect sci-fi films that come out in about 2-3 years to have scenes that closely mirror the look of the re-entry and descent of this Falcon-9 because people know “that’s what it really looks like”.
Felt just like watching a launch in Kerbal Space Program to me, especially the landing burn.
Space-X are no longer the amatures playing in the big boys sand box (if they ever really were) they are clearly now the big boys. The landing footage was beyond amazing, especially the close up shots achieved in the last minute before landing, Anyone who is not inspired by this simply fails to understand the significance of what Space-X is doing.
Clearly the big boys?
NO…..Not yet.
“NO…..Not yet.”
When I see a delta, Atlas, Arianne or any other Orbital rocket land it’s first stage back at the launch site or on a floating barge in the middle of the ocean then I might agree but when the Falcon Heavy make its debut the only things keeping the old school in the business will be pork and Intransigence.
Reminds me of the scene in Star Wars where Darth Vader revealed to Luke that he was his father. Luke screams back “Nooooooooo, that’s impossible!” Well, the impossible just happened. A big domino just fell.
The shots of flames wrapping back up the booster during the entry burn and landing make it clear why it becomes so sooty.
Now imagine the space shuttle performing the same sort of burn during a Return to Launch Site abort. I’d have hated to have been riding in an orbiter flying backwards into SRB exhaust (which would contain aluminum oxide and other nasty stuff).
In an RTLS profile the SRBs were shed before any flyback maneuvers were executed. Only the SSMEs were used for thrusting back towards the launch site.
You’re right, so the shuttle would have been flying backwards through H2O and other various gasses. That’s not quite as bad, but still it was never done as a test.
T.K. Mattingly had wanted to fly an RTLS for OFT-6, or so the scuttlebutt at JSC indicated. OFT-1–4 was it, though, so no RTLS proof-flight.
Would NASA have been able to iterate a landed first-stage system as quickly, or would it have languished in NPR 7120 hell every step of the way?
Yes. It was called Liquid Flyback Booster. Killed by politics.
NPR 7120 is always worth blaming. I don’t know if that document had its current name and number, back when a liquid flyback booster was under consideration (either time.) But some similar document would have dictated how NASA would manage its development. That plays into the cost and schedule, and that plays into the politics not to develop a liquid flyback booster.
Just wow! That’s some sweet footage for some future POP videos. It looked like the boost back burn starts with one engine, 7-8secs later the other two light up.
To quote Jack O’Neill from Stargate, “That just never gets old”.
And those camera shots from the ground were amazing.
just amazing … the speeds, the neat use of aero-braking; and this is now routine ! I wonder why they don’t use parachutes ? reliability ?
For one thing, precision. The booster needs to land on a stable surface near recovery facilities. A booster descending by parachute would still need to be steered, so now you’re adding aerodynamic complexity.
That and the landing loads caused by coming down via parachute are quite high compared to a powered landing. This is why the Soyuz capsule uses braking rockets right before landing. If those braking rockets don’t fire, the crew survives, but will quite likely have some injuries due to the high-G impact.
They already have to restart the engines for the boostback and re-entry burns. Why use two systems when one will work just fine?
BTW, they tried to use parachutes to slow the re-entry on the earliest F9 flights. It doesn’t work — the supersonic airflow simply shreds the ‘chutes.
The speeds, indeed. There’s nothing in that video to inform a viewer just how terrifyingly fast everything is moving. It is a stunning piece of engineering the looks dead simple.
But the simple part – I’ve just finished reading Vance’s book on Mr. Musk – the really astonishing part is the concision that it could be done at all.
Yes, great job SpaceX!
Can anyone characterize the fuel load or payload hit required to return the first stage? An extra 10 or 20% fuel and oxidizer, or a ? Just trying to get a feel for how ‘hot the rocket needs to be in order to fly back.
I guess I was also surprised to watch the stage slow so dramatically without the rockets as it approached the landing zone.
that was aero-braking of the landing legs, no?
A bit, but they’re not deployed until very late in the sequence so any “aero-braking” by the legs is minimal. The final braking is done by a burn of a single Merlin engine.
I thought they slowed on landing (from 40,000′ down) without using the rocket (no obvious flame) as the atmosphere got denser. The landing legs look like pretty good dive brakes.
They’ve got those air brakes that pop out. It was really interesting to watch the velocity drop before the final burn, though. Be interesting to see if they eventually go with a single suicide burn to reduce propellant requirements.
Watch the video again. The grid fins at the top of the stage are quite “draggy”. They also swivel to provide aerodynamic control of the stage, so they’re deployed quite early during atmospheric descent. Perhaps that is what you saw?
The landing legs, on the other hand, are deployed only a few seconds before landing. Also, the landing burn starts well before the legs are deployed. At that point, the braking of the stage comes mostly from the single Merlin engine, which in fact at its lowest thrust setting has a thrust higher than the stage weight during landing.
Watching the video closely, the landing legs deploy mere seconds before touchdown on the landing pad. So no, the landing gear is not designed to act as “dive brakes”.
yes, not the legs but a dive brake mount on top of the rocket, and probably more predictable than a parachute. still it’s aero-braking, no?
No. The grid-fins are primarily for steering at super and hypersonic speed. They were invented by the Russians for ballistic missiles. Lighter than vanes and more effective over a wider range of velocities.
http://www.spaceflightinsid…
[And grid-fins on an SS-20 ballistic missile:
https://c2.staticflickr.com…
The whole stage is aero-braking because it’s a mostly empty, very large, aluminum can. The grid fins were added for control purposes. Any braking they perform is a bonus on reentry. But also note that the grid fins are literally a drag during launch, so they stay folded against the rocket body until they’re needed.
I was glad to get numbers (and a visceral feel) for the boostback and re-entry burns. The re-entry burn decelerates from 1400 m/s to about 750 m/s in just under 25s, which works out to under 3 g’s. The atmosphere thickens significantly close to the planet which accounts for the rapid deceleration through the transonic regime. I’m awed to consider that somewhere is a small group of humans (probably no more than a dozen) who worked out the maths for this.
Yes, the drag fins, I don’t think I realized just how dramatically they slowed the vehicle, wrongly assuming that they were there mostly for control.
Does anyone know the dry mass of a Falcon 9 first stage? It wouldn’t be hard to estimate the fuel used to recover it, if I knew that (and an initial velocity of 1.4 km/s.) The only thing I can find online is the wet mass.
It’s one of the things that fanbois have been trying to work out since F9 first flew.
Estimates for the entire F9FT stack are 25.6 tonnes inert mass, 409.5 tonnes of prop. (3.9t dry/92.7prop for the upper-stage.) But vary wildly between sources (and F9 versions).
Well, that’s enough for a ball park guess. 1.4 km/s at the start of the initial burn, 311 seconds specific impulse in vacuum (or near vacuum). A purely propulsive burn to kill all of that velocity, leaving a 25.6 tonne empty first stage, would take 15 tonnes fuel (14.9 to be precise but not accurate). They save some, since part of the slowing is from atmospheric drag; they loose some, since they have to fight against gravity, turn around and go back, not just slow to a stop. But I think it’s safe to say it takes less than 10% of the initial fuel load. (I guess I could improve on that calculation if I checked how long it takes to fly back. I.e. the time of the initial burn compared to takeoff and landing. But this sort of estimate isn’t going to get better than a factor of two, so I won’t bother.)
That’s actually quite a bit less than I expected. I may have done something wrong, but I can’t find an obvious error.
Of course, that doesn’t directly translate to reduced payload (i.e. what they could loft if they didn’t try to return the first stage.) The flight profile that allows that 1.4 km/s initial velocity may be, in and of itself, a compromise to trade payload for ease of return.
It does in that you aren’t using that extra fuel to accelerate the upperstage/payload more before staging.
Musk has estimated a payload loss of 30% for F9 first stage reusability. And they use 1/3 for FH GEO capability, ie 8t instead of 24t. (Musk has also estimated 40% payload loss for full F9 reusability, including upperstage.)
Saving 10% of the propellant is functionally equivalent to having a much higher dry-mass first-stage with a slightly smaller prop load.
Which would be a way to double check the figures. Using a launch-calculator to get an approximate payload for expendable launch, based on the “known” figures. Then shift propellant-mass to first stage dry-mass until the payload drops by 30%. But given the nature of the rocket equation, doubling the pseudo-dry-mass of the first stage and seeing a 30% drop in payload, seems a reasonable scenario.
It’s that 30%/40% figure that got me thinking and asked the question, scratching my head – “can’t be true”, as it would imply a very very hot engine, and a serious energy bump from super cooling.
And now I am bumping up against my paltry physics limit.
By “[extra fuel use] does not directly translate to reduced payload”, I meant the relationship wasn’t one-to-one. A 30% hit to payload capacity isn’t at all surprising for only burning 90% of the fuel in the tank.
Musk threw around 30% before they actual did it. They “paid” for it by extending the prop-tanks and improving the engines.
The ‘entry burn’ is key to Falcon’s survival. The three engines fire just before the booster hits the thick part of the atmosphere at its highest descent velocity. The lit engine’s pressure wave protects the booster and by the time the engines shut down, the booster is going ‘slow’ enough to survive the friction heat from the atmosphere. The entry burn also allows the booster to correct its trajectory so that the drone ship or landing pad is well within the range of the grid fins to guide it down to a where the landing burn begins. It looks like the single engine, the grid fins and the nitrogen thrusters all come into play to achieve a pinpoint landing.
Hmmm. Absolutely spectacular camera work tracking the vehicles, most of it never having been seen before. Looks like SpaceX may have recently obtained some amazing new tracking hardware. Or did they happen to borrow some from its customer for this one? 🙂
No, it’s just that on previous flights, they track the second stage since the primary mission is paramount. In case something goes wrong they want that high quality footage of the second stage.
But, on this mission, since it was NRO, SpaceX wasn’t allowed to keep tracking the second stage after separation, so that is why this is the first mission that tracked the first stage from launch to landing. If anything did go wrong, no doubt the government has their own cameras for that contingency.
Elon said the final version of Falcon 9, to be ready to fly by the end of the year, should do 10 flights just with refueling, and 100 flights if light maintenance. If this is right, we have a revolution in our hands.
And none too soon, from my perspective.
And Shuttle was going to fly 50+ times per year with ground turnarounds of 160 hours. Then reality intervened.
Optimism is great, but…
True enough. But this is based on actual date from recovered rockets, not on projections made during the design phase, as in the case of the Shuttle. And the Falcon 9 is a design from the early 2000s, and not the early 1970s.
Even if SpaceX is being optimistic, it is being so bringing all the market with it. Blue Origin will also fly reusable rockets, ULA announced its new Vulcan rocket will have a reusable engine, Arianespace is considering reusability for its Ariane 6… I’d say the revolution is already happening. What we don’t know is how far it will go.
We shall see…or not.
I do not disagree with most of your points, but I remain wary of rosy projections from very limited data.
There was a panel after the SES-10 launch where someone from SpaceX said this reuse had reduced costs by at least 50%.
SpaceX’s incremental approach to development of reusability makes a lot more sense than the Hail Mary attempt of the shuttle.
The difference is, F9 without reusability already revolutionised US spaceflight. It has already succeeded. Reusability is a bonus.
The STS was too expensive to use more often, and too fragile to risk on anything dangerous.
I think the shuttle experience is not correctly understood. The shuttle did a couple of things poorly, which prevented it from being COTS.
On the other hand, it definitively proved that engines and aerospace structures could fly to orbit, and be reused. There was literally zero effort put into fixing and evolving the design to make the engines, foam or tiles more robust. Nevertheless, the orbiters flew 20+ missions each, OMS engines had hundreds of starts, SSMEs flew 10s of flights.
The commercial analogy is that SEARS proved you can’t do online shopping. No, SEARS proved THEY can’t do online shopping, not that online shopping can’t be done.
The moguls over at Lockheed and Boeing must be fuming like a LOX tank now that the upstart has horned in on their lucrative government-military-intelligence launcher monopoly. I’d like to think that chairs were thrown and curses hurled at ULA ‘s throne room.
The gorgeous uncut video from the long range tracking cameras all the way from launch to landing – even when the Falcon was more than 100 miles up ! – was an opus of magnanimous scale. Kudos to whomever or whatever was able to stay locked on the booster for one of the most amazing live videos I can recall.
I have a profound new sense of the strength and precision of the cold nitrogen maneuvering thrusters. W-a-a-a-y more powerful than I expected. They are what makes the whole high alpha turnaround and return dynamic possible. Wow. Watching the realtime altitude and velocity readouts were informative.
Anybody know if there was an attempt to track and recover the fairing shells ?
A user on NSF reported back-channel info that they recovered a fairing half. Only trying for 1 for now.
Walker and Gingrich are not making any friends calling for not using
expendables anymore.
Good. I’m glad more and more people are finally starting to call out the emperor for having no clothes. The fact that NASA’s PAO keeps saying SLS and Orion will take us to Mars is getting very, very old. That hideously expensive (expendable) of a lunch vehicle and bloated capsule that doesn’t even have a heat shield rated for reentry from interplanetary speeds aren’t going to help get us to Mars.
There’s very little risk in taking that position. For anybody outside of the space community it will seem to be visionary.
Something that I have been wondering about for a while, but never got around to asking about it until now. The F9 has grid fins to provide drag to slow the stage down during descent, so less fuel is needed to do that. But the landing legs pop out at almost literally the last second. Couldn’t the legs be used to provide a bit more drag if they popped out a bit earlier?
Above a certain velocity, they’d probably be damaged by the slipstream. Certainly aerodynamic forces would stop them from extending properly.
The legs are at the wrong end. If you put the drag at the “front”, it’d make the stage want to flip over.
National security requirements can get strange. Officially, no one involved in the launch was supposed to comment on the satellite’s planned orbit. Anyone can figure that out a soon as it’s launched. All you need is a pair of binoculars, a clock and access to equations found in physics textbooks or on wikipedia. The fact that anyone could track the second stage doesn’t mean the launch service provider wasn’t told not to do so. Stranger things have happened.
Actually, a cell phone with high quality motion sensors, compass and GPS is all you need. If you can calculate the rough distance from the cell phone and the launch pad, just keeping the launch vehicle on the screen would give you the data needed the calculate the launch path until you lose sight of it. Three or more cell phones at different locations would give better data and be also be allow for error correction as well.
Someone should write an app for that! 😉
DOD policies don’t have to make sense, SpaceX just has to follow them.
I misunderstood. I haven’t checked the numbers, but I strongly suspect the rocket is below the horizon (from the Cape, and probably from anywhere on land) at the time of the initial reentry burn. If that’s correct, then anyone wanting to make a landing video would have to reacquire it when it came back over the horizon. For SpaceX, that would be easy, since they are tracking it by other means. For someone on the beach with a telephoto lens, that might be tricky. But not impossible. Maybe no one thought of trying until you mentioned it.