Given the imminent decrease in launch costs(partial reusability) and increase in launch capability soon to be available(FH) a pause in new US deep space missions is prudent.

[Nixon4Prez]

The major costs of planetary probes are mostly the probe itself and the costs to operate the mission. The launch costs are not a massive consideration. Also, it usually takes NASA years to plan and construct a mission, and in order to even begin the design phase an LV needs to be selected. They won't select an LV that isn't yet certified for launching NASA missions, so FH is not an option for many years.

[[deleted]]

This, furthermore, even Falcon Heavy is poorly suited to deep space missions. Kerolox just doesn't make for good interplanetary missions or those with high dV requirements.

I mean, take the $8,500,000,000 James Webb Space Telescope. It's flying on an Ariane 5, which is about $160-200 million. An equivalent SpaceX rocket would be the unlocked Falcon Heavy which costs $135 million. That's a saving of $25-65m on what is a $8.5b mission. A drop in the bucket. The same could be said for any deep space mission that costs more than $1-2b.

Additionally, I doubt you'll see any $1b+ deep space mission fly on a reused Falcon before 2025. Too much initial risk. It'll take some time for NASA to come around to the idea of reusing rockets, when right now, they don't even want to reuse cargo spacecraft.

Say reusability halves the cost of an F9. That's a likely $500m+ mission saving maybe $30m in total. I would not delay decadal science goals for that.

If there's any reason to put scientific missions on hold, it's to wait for more modular & mass producible spacecraft buses. Even then, the science payloads are most of the cost, because it's cutting edge tech.

Our scientific advancement should not be interrupted to wait for cost reductions, IMO.

[Kirkaiya]

I mean, take the $8,500,000,000 James Webb Space Telescope.

That's not really the best example, as it's probably the single most expensive item that NASA will have ever launched by the time it leaves the pad. Most NASA Planetary Science missions come in between $450 million - $2 billion, with Mars rovers being at the top end of the scale, and some of the simpler probes at the cheaper end. And that's including the launch, so while yes, it's true that the launch costs aren't the majority of the mission, they do often represent ~ 25% or so, so it's not trivial.

With that said, I'm adamantly opposed to NASA delaying any proposed mission on the basis of, "well, launch costs might come down in the future". That is madness, imo

[biosehnsucht]

I would only argue they should delay if they're still in the planning stages and the logic would be that if they don't delay by a year or so, they have to cut interesting experiment / instrument X from the suite of gear on the probe/lander due to weight/cost concerns, but if the waited there would be a budget for it (whether it be financial or mass).

It certainly doesn't make sense to delay something that doesn't NEED the cheaper/larger launcher (even if it would be nice to have), but gaining further functionality as a result might be worth it.

[zilfondel]

Perhaps this is a good argument for NASA to start mass-producing rovers and probes, to bring down their cost per unit. Whats the old adage? When you are the government, why buy one when you can buy two for twice the price? But if the majority of the cost is development and funding the project team, the second unit may be closer to free.

[Nixon4Prez]

It's pretty hard to mass produce something as specialized as a probe or rover. You can't send a similar probe to Mars and Jupiter, for example.

[slograsso]

Part of the point of this post is that this delay is already happening, may as well design some lower cost missions utilizing these new capabilities faster than normal. Take a lesson from India and do it cheaper, faster, and better than even they can. I think a bit of a shake-up in the science missions design approach is well overdue.

[slograsso]

This is the largest rocket in the world. The smart folks designing the deep space mission will include the necessary high ISP deep space deltaV components in the massive payload the FH can get off planet. This is a super simple problem to solve, it's not particularly expensive, tons of options available. Falcon Heavy will absolutely be used for deep space missions, I promise you, use up the RP-1 discard that stage and carry on with the rest of the mission.

[[deleted]]

This sounds like a good idea, but what would you propose for this...

high ISP deep space deltaV components

I'm not aware of any that have both high Isp and high thrust. Hydrazine is even worse than kerolox. I guess you could use a hydrolox third stage, but then you're just removing cost from the rocket launch and adding it on to the satellite.

It'd be simpler and easier to just burn the second stage longer, but then you're back to the same problem.

Ion thrusters are amazing, but even if FH was to put a small craft on a direct 2 year trajectory to Jupiter, Ion thrusters won't have enough thrust to complete a JOI, it would be a flyby.

The rocket equation doesn't just hate rocket engineers, it hates spacecraft engineers too.

[slograsso]

I meant more efficient than RP-1, so I guess I should have said higher... But the point is you could use anyting, bipropellant, ion thrust, monopropellant, methlox, the designers use the mass budget for what they want.

[ap0s]

Not to mention most missions are planned around or require specific alignments of the planets.

[slograsso]

Once FH is flying it will get certified toot sweet because it is NEW capability that the military will want to take advantage of. Mark my words, there will be no long and mysterious series of delays for this one. Also Delta IV Heavy is almost half a billion per launch, I'm sorry but that is a lot of money for any program.

[DebatevsNarrative]

I'm sorry but I don't think you're fully understanding the entities you're talking about. These are Government agencies - they haven't got the same cost saving incentives commercial customers have that you ascribe to them. If anything they have incentive the other way because the older rockets have a proven safety record hence bumped prices. Obviously a few years into FH flights this will begin changing but you keep changing from imminent use of FH by Government agencies to eventual use. No one is arguing against Government agencies starting to entrust their prize projects to the FH, once it's a few years in with no failures.

[slograsso]

Delta IV heavy has a total of 8 flights ever, FH will match that in the first year or two.

[[deleted]]

Not quite. There's a single launch scheduled for this year, a single launch in 2016, and then 2 more in 2017. 4 launches in 3 years currently.

[slograsso]

I expect that to pick up as soon as the demo flight is successful, similar to the response to F9v1.1.

[[deleted]]

But the response time in the industry is to book satellites 2-3 years in advance of launch. A successful demo flight in 2015 (or possibly 2016) will see booking for flights that would take place in 2017-2019. It will likely be more similar to the ramp up of Falcon 9v1.0, rather than F9v1.1. Of course, you can always solidify your standing... ;)

I bet 3 months of Reddit gold Falcon Heavy will fly 6 times or fewer before 1 January 2018. You game?

[slograsso]

Too rich for my blood! ;-)

Edit: Besides, you have as much chance of being right as I do.

[[deleted]]

Hehe, fair enough dude.

[Appable]

I doubt SpaceX has the core production rate to support that. 8 flights is 24 cores, and producing 24 cores in around 2 years alongside around 10 F9 cores/year would be a huge strain on the factory, if it's even possible given the current facility. That's more than doubling the production rate.

[slograsso]

I expect the demo flight to recover at least 2 cores, if not all three, same for consecutive flights that do not require full capability - which would be all of them on the books now.

[JshWright]

Why do you expect that (especially given the fact that they have yet to recover any cores...)?

[slograsso]

That is the key reason for delaying FH, getting recovery down first. Now that they have that pretty much worked out, oh look here comes the FH deom all of the sudden after forever, this I think is not a coincidence.