OK, back in the office after over a week of travel to DC and the Bay area.
Over in this comment thread, the question arises of the disposition of the first-stage from last week’s launch. I was wondering too, so at the gala banquet at the Air and Space Museum on Friday night to honor John Glenn and Scott Carpenter, I asked Stephanie Badnarek, director of government relations for SpaceX. As I suspected, she told me that they’re not worrying about recovery of the first stage right now, and probably won’t until they start to attempt to fly it back, pending results of the Grasshopper flights. That wouldn’t surprise me — I don’t think they’ve come even close to an intact entry, and the recovery systems are just parasitic weight at this point.
[Update a couple minutes later]
Clark Lindsey has some notes from the SpaceX press conference on the mission so far, and plans for Dragon entry tomorrow.
NASA contracted for all new Dragons for each ISS mission.
Wow. That seems to indicate they’ll be quite a few used-once Dragons lying around eventually.
That they own the Dragons they fly has been public information for quite a few years, and is one of the reasons why it’s easy to see how they can price crew flights so low and likely make a decent profit.
Most likely the C1 and C2+ capsules will be deemed retired, but the 12 CRS capsules will become the foundation of fleet going forward. If every capsule is good for ten flights, and they essentially broke even in building them for the CRS program, that means they will have 108 future flights that will be essentially zero cost and all profit for the capsule part of the system.
Heck of a business plan.
Might want to read Lar’s comment further down.
I wonder how much a used Dragon capsules could be bought for. Someone like Excalibur Almaz might want to use them to send tourists to the moon…
If nothing else, or perhaps as the final market at the end of service life, they could donate them to museums as a charitable contributions. A space capsule that’s actually flown people into space would be in high demand. Most of the Dragons wouldn’t be so historic that a museum wouldn’t let people climb in and sit in the seats for a simulated mission, either.
IIRC SpaceX keeps the used d Dragons.
Which will make their DragonLab flights very profitable.
It won’t be as huge of a difference as some expect. These Dragons are not reusable as in “fuel hypergolics and launch” – they do have to take it apart and inspect, and then reassemble – Just like the Shuttle.
Not quite like the shuttle. They could part out the whole craft and use it to build others and still have a huge cost savings. Which makes one wonder if some backyard mechanic could reconfigure those parts for something else. This could be the beginning of space RVs.
Hmmm. Space RVs. Kinda like this?
The Dragon is a far less complex vehicle than the Shuttle, and the RCS is on the exterior of the pressure vessel. There is not a lot to inspect and refurbish, and they have built their systems to be reusable.
If they were really concerned with the fuel system, they could just install new tanks and new fuel lines. Not a big cost driver.
Why would the fuel system have much wear and tear on them at all? (other than pumps perhaps?) That part should be just gas and go.
The Dragon’s Draco thrusters use pressurized hypergolic propellants (the same as the Shuttle and most other spacecraft. Hypergolic propellants are corrosive and toxic, so a inspection is a good idea. I don’t think (but I’m not certain) they replaced all of the Shuttle OMS and other hypergolic propellant lines after each mission (but that might explain why it took a standing army to prepare for each flight) so it seems unlikely SpaceX would need to do so either.
IIRC, the reusable Falcon first stage would have to detach from the second stage much earlier, at a lower speed, for flyback to be feasible. Since they aren’t doing that for these ISS launches (are they?? I’m assuming not), it would be pointless to even try.
From memory of a conversaton with a SpaceX employee last year, these first few Falcon 9 flights are using the lower powered Merlin C engine. Before long, flights will use the considerably more powerful Merlin D. That should make a difference in the flight profile.
Recently Musk talked about Falcon 9 v1.1, which will have the Merlin 1D engine and a longer body – more thrust, more fuel, and a much bigger payload to orbit capability. It’s not advertised on their website yet, but Space Launch Report has pulled together the public information on it.
From what that employee told me last year, the information in the information on the SpaceX Falcon 9 webpage and in the User’s Guide is already based on the Merlin D version because all of the F9s with Merlin C were already booked.
I’m much more interested in the -second- stage.
As far as I can tell, it makes it to a (crummy) orbit. Do they do a deliberate deorbit? And where is it supposed to come down?
It can’t be too crummy an orbit, because the Dragon doesn’t have all that much fuel on board for big orbital changes. IIRC.
“target orbit with a low point of 310 kilometers (192 miles), a high point of 340 kilometers (211 miles), and an inclination of 51.6 degrees.”
ISS is at 250 miles up.
Can’t decide how long the second stage might be able to stay up though.
From last week’s coverage about the human remains launched on this mission, the second stage will stay in orbit for about a year. It has a pretty high surface area to mass ratio so its orbit will degrade fairly quickly. Also, the Dragon fires its thrusters to pull away from the second stage at separation. The rocket body is quite a few miles lower than the ISS. According to the Heaven’s Above website, the second stage is in a 265 x 319 km (164 x 198 mile), 51.7° orbit.
Now the bonus question.
Replace Dragon with a fuel pod. (Or leave the ‘third stage’ off entirely).
Can the entire second stage make it to a more long-term orbit? And be renamed “Propellant Depot #1?”
Or does this entire line of wishful thinking require FH.
The second stage isn’t well enough insulated to store LOX for very long. It just wasn’t designed for that. Replace the Dragon capsule with a properly designed propellant storage system and you could put several tons of propellant into orbit. The Dragon literature says it can carry 6 tons of supplies to the ISS. Leave off heavy and unnecessary systems like the heat shield, parachutes, etc. and you might be able to put close to 7 tons of propellant into LEO.
If you’re going for storable (hypergolic) propellants, you could use the existing Draco thrusters to have a reasonable space tug. Add the proper systems (attitude control, TT&C, electrical, thermal) along with a grasping system and you could do things like move satellites around, perhaps to deorbit dead rocket stages and satellites or to boost still function LEO satellites to higher orbits as their propellant supply runs low. I’d think such a system would cost a lot less than a Dragon capsule. Something with that much propellant would have a lot of delta-v potential.
Perhaps the NRO would have use of that service. I proposed such a system to them in 1987 but to my knowledge, nothing was ever done with the idea.
It you took a Draco thruster with a minimal control system and a fuel tank shaped like the nozzle of a larger engine, it could be shoved into the engine bell of most spent upper stages, simplifying mounting and attachment. Your satellite could rendevous with spent upper stages, orient them and insert the deorbit (or boost) Draco and then back away. That way your satellite doesn’t have to undergo the same delta-V as the object being deorbited, so you could have quite a large number of Draco boost stages to attach to many different objects (kind of like a MIRV bus).
I’m thinking more along the lines of “Propellant Depot/Earth Departure Stage” as opposed to a more permanent structure.
A fully refuelled Stage 2 in the currently achievable 200 mile orbit would be a whole other magnitude of ‘a lot of delta-v’.
The second stage isn’t well enough insulated to store LOX for very long. It just wasn’t designed for that.
But could it usefully be retrofitted with additional insulation on-orbit (Mylar MLI, aerogel)?
A dozen ex-CRS F9 upper stages, grabbed by tug and moved to a Bigelow contruction yard — the basis for a tidy little BEO transport business? 😉
Again, I don’t think that would work as a depot. Even with additional insulation and sun shades, I suspect LOX boiloff would be too great. However, if you could gather up the spent second stages (assuming SpaceX’s plans for recovery don’t pan out) and refuel them from a depot, they could be used as powerful tugs themselves. You could boost payloads from LEO to GTO and beyond or do other missions.