NASA Picks 4 Discovery Missions For Concept Studies
NASA Selects Four Possible DIscovery Program Missions to Study the Secrets of the Solar System
“NASA has selected four Discovery Program investigations to develop concept studies for new missions. Although they’re not official missions yet and some ultimately may not be chosen to move forward, the selections focus on compelling targets and science that are not covered by NASA’s active missions or recent selections. Final selections will be made next year. NASA’s Discovery Program invites scientists and engineers to assemble a team to design exciting planetary science missions that deepen what we know about the solar system and our place in it. These missions will provide frequent flight opportunities for focused planetary science investigations. The goal of the program is to address pressing questions in planetary science and increase our understanding of our solar system.”
Two Venus missions! I hope they work out in the next phase – we’ve had a paucity of US Venus missions for years, and both sound very interesting. I’d love for one of them to get the final pick.
But really, all four should be funded. Discovery Program missions are cheap but highly effective – Congress could easily authorize funding for more of them.
Interesting. Two Venus missions, two outer solar system missions and no asteroid or comet missions. That’s an unusual mix. The timing for selections is a little awkward for ice giant missions. That’s going to happen at about the same time the Decadal Survey panel will be prioritizing possible, larger ice giant missions in the 2030s.
Think the 2 Venus mission will morphed into one mission. With an orbiter bus for the VERTIS observations dropping the DAVINCI+ sampler capsule into the Venusian atmosphere. After all you need some sort orbital platform to retrieved the data from the DAVINCI+ death plunge.
The cost for a dual manifest Venus mission should be less then for 2 separate missions. Especially since the expected lifespan of the DAVINCI+ probe should be a few hours after contacting the Venusian upper atmosphere.
Call it Pioneer Venus 3! Although, IMO, Magellan should have been given that mission title.
Technically, NASA can’t do that. Or, at least, it would be extremely difficult. The Discovery program is an established (and congressionally approved) way of selecting and doing missions. Selecting two, similar ones and merging them isn’t part of that. It could be done if the President and Congress said so, but they’d want to know why. Especially since the National Academies have endorsed a balance of Discovery, New Frontiers and flagship missions as the right way for NASA to do planetary science. I don’t think anyone at NASA would even bother suggesting a merged mission.
On the other hand, NASA could select both, could even co-manifest them on the same launch vehicle (although it would have to be a big one…) and could even cite coordination and synergy as a benefit. I’m not sure about the downlink, but I believe DAVINCI+ can do direct to Earth transmission. At least, past, similar concepts have found that it’s possible. The DAVINCI+ payload isn’t data volume intensive, and the decent is only a bit over an hour. But I suspect, for reasons of the scientific community’s expressed opinions and for “programatic balance”, they’re going to select one Venus and one outer planets mission.
The folks from Hawthorne have such a launch vehicle available for dual manifested Venusian flight as well as for a Triton flyby. Of course they need certification for carrying Nukes first for the flyby.
We shall see.
Venus is actually very easy to get to. I probably should have been more careful about saying it would take a “big” launch vehicle. A Falcon Heavy (recovered) could probably get both VERTIS and DAVINCI+ to Venus with mass to spare. And rating them to fly radioactives isn’t an issue for Venus missions.
Both TRIDENT and the ATM probe are heading for Venus
You could fly them together 🙂
Steal the TMAP from Io orbiter for Trident for the Io flyby
FWIW, in the ‘Flagship’ level, I’d love to see the occasionally-proposed Uranus flyby and atmosphere probe (which would then travel on to a TNO) get funded.
The timing for that is not looking good. There was a workshop on ice giant exploration last month, and we heard about (and debated) some of the problems. NASA isn’t in a position to start work on another flagship (technically large directed) mission in the next couple years. After that, it would be in the 2023-2032 period covered by the next Decadal Survey, and we have no idea how high a priority such a mission will be.
At the meeting, we also talked about involving ESA. They don’t have the resources to do an ice giant flagship on their own, but they could contribute substantially (as they did with Cassini-Huygens.) But that would add a few years, since they can’t commit to anything without some approval at the ministerial level. If memory serves, that’s a three year cycle, and it would have to be at the meeting _after_ the US Decadal Survey came out _and_ NASA officially decided to proceeded with whatever it recommended. With luck, that might mean a start of phase A in 2025. Probably later.
Unfortunately, that means it probably wouldn’t launch until 2035. I think it’s possible to speed that up, but I don’t think NASA would be willing to do so with a flagship mission. The recent study on ice giant missions found that the opportunities (planetary alignment) for Jupiter gravity assists goes bad for Neptune around 2032 and for Uranus around 2034. After that, they didn’t see anything viable for at least another ten years.
That was debated. The study made a number of assumptions, some of which could make a big difference. To be fair, they didn’t have a choice, since those assumptions were written into the study’s charter. They did not consider launching on an SLS, and some people though that might be an option (I don’t.) They didn’t consider launching on Starship (and the consensus was that we shouldn’t count on it until it’s flown.) Aerocapture wasn’t considered. And there was a maximum duration for the missions they could consider. A couple extra years of cruise and possibly an extra Earth gravity assist might make a difference. So the study’s 2034 deadline isn’t necessarily a hard one. But for a flagship to Uranus or Neptune to happen any time soon, it probably needs to be the first thing NASA does after the Decadal Survey comes out.
The Trident Discovery mission also came up (naturally) and there were some mixed feelings about it. No, that’s not quite right. Everyone though it would be great. But there are only so many things a flyby can do well. There is a long list of things an orbiter could do well, which a flyby either can’t do at all or can only do poorly. That’s fine, and Discovery missions aren’t expected to do everything. But there was concern that Trident could make an orbiter a lower priority in the Decadal Survey. I don’t think anyone thought NASA should do a Discovery class flyby and then decide the ice giant box had been checked off.
I understand why you should not develop a proposal that requires untested systems, but I’m really curious how much the calculus will change once Starship and Super-Heavy are online. Add to that, the recent article about Ad Astra Rocket Corp. (Chang-Diaz’s high-power ion drive company) getting to TRL-5 and heading for 6. Things could get pleasantly interesting for deep-space missions, if the cost and time to get to the ice giants were brought down significantly.
What Starship would do for an ice giant mission is hard to say. NASA basically couldn’t use it if they developed the mission as they have developed past missions. That is, by trying to squeeze in as much capability as possible. That’s expensive, to the tune of perhaps $1 million per kilo (unfueled). NASA’s whole budget could go to developing a payload that way, without coming close to the full capability Starship is supposed to have. If Starship works out as planned, I’m sure NASA would use it, but using it would require such a fundamental change in the development approach, that I don’t think it’s possible to predict what the end result would look like.
For electric propulsion the current, TRL-9 state of the art is fine. The problem is power, especially for an outer solar system mission. If you need 25 kW per Newton of thrust (the NEXT Kaufman thruster), acceleration is limited by the mass of your power supply. (Ad Astra’s VASIMR is actually worse, at about 40 kW/N. Hall effect thrusters used by communications satellites can be better.) Nuclear power of any sort is too massive for the power it produces. Solar is ok, but you have to do all the acceleration in the inner solar system. (And that introduces a need to throttle the thruster way down as you move away from the Sun.) Fortunately, communications satellites are pushing the state of the art for both Hall thrusters and low mass solar arrays.
I see your point, if NASA follows its general patterns (which it tends to do unless acted upon by an overwhelming force), that an even larger extremely expensive probe will just be even more expensive. I think part of my internal primeval engineer was thinking: “put a big honkin’ engine on it”. More sanely, if you don’t have to hyper-specialize and shave every unnecessary ounce off a mission, you should be able to save some serious money.
As for VASIMR, Ad Astra Rocket Co. has an interesting white paper on their site, where they admit that on the small scale, cold-gas Hall-effect thrusters are more efficient, since VASIMR’s power systems do not scale down well, but above 50 kW, VASIMR scales up better. Regardless, any high-power ion engine system would likely need to get boosted some ways away from where a large stream of c-fractional ions won’t do untoward things to satellites or space stations, so again a big launch vehicle like Super-Heavy would be nice.
I agree that current space nuclear power (RTGs) are too much of an intertial penalty. I’m salivating over what future generation systems could provide, (LM Skunkworks Energy division, don’t let us down), but cool designs on paper do not make for a practical solution in the near future. What is available for planning purposes in the 2030’s, remains to be seen.
That leaves solar for now, but given the wacky orbital mechanics NASA has been forced to use of late to place their missions with a minimum of available delta-V, an SEP system that uses a lap or two around the inner solar system to build up speed before sling-shooting outbound to the gas giants does not seem that ridiculous.
My main point was that increasing up-mass increases options, and I am curious if anybody is interested in exploring those options now, rather than wait for the proverbial bird to be in hand before reconsidering plans that are too far down the road to justify changing them.
I wonder if there are any Jupiter solar trajectorys post 2034?
Just not to close to the Sun as the 500 AU missions desire.
Solar flyby at .75 AU
By that time maybe there might be a Starkicker upper stage/interplanetary transit stage available for very high energy trajectory.
Starkicker was concept floated by Musk with a stripped down Starship stage with more tankage with no reentry or landing hardware. So should be able to be top up with propellants in orbit. As well as propellant transfer during transit.
If each Starship is as cheap as Musk estimates at about $40M to $80M as I recalled. The Starkicker will be even cheaper.
So in theory you could fly a formation of Starkickers from a Lagrange point to one of the outer planets for gravity assist maneuver. With one Starkicker that have it’s tanks top up from the other Starkickers enroute to the outer planet. Should be able to send payload of a few tonnes to anywhere inside the orbit of the Kuiper belt in a reasonable period of time.
If there is enough budget, could even start with enough Starkickers to do multiple gravity assist maneuvers. Expending Starkickers like drop tanks.
Hopefully the Starkicker will enters service in the late 2020s.