The test is essentially a success at this point. Starship can take payload to orbit and open/close the payload doors. The remaining things are icing on the cake. They can refine re-usability while flying payloads.
Normal orbital insertion is a single burn to orbit (with staging). With the correct initial roll and pitch, the spacecraft follows a perfect gravity turn and ends up in a near circular orbit at main engine cut off.
The rocket yaws and pitches in the first seconds of flight while the vehicle is still subsonic, then flies a gravity turn trajectory at zero angle of attack (facing the direction of travel) at near maximum thrust. Any errors accumulated during early part of the flight will be corrected by adjusting the timing of the second stage cutoff based on radar tracking.
The initial pitch over is just a few degrees off vertical, but must be precise to a fraction of a degree (KSP tolerances are higher due to small planet).
You can get a pretty good circular orbit in Kerbal Space Program with one burn if you do a few attempts and trial and error binary search for the optimal initial pitchover angle, but it's very difficult to do without throttling the 2nd stage burn. If I recall correctly, the MechJeb mod can do a precise single burn to orbit.
Finding the correct number of key taps to get the right pitch angle is the key. The throttle can only help so much.
Thank you. Though I don't expect to open KSP any time in the near future, I love to know how the real rockets do it.
There are reasons "apogee" is more recognized word than "apoapsis".
What are you getting at? The -gee suffix means Earth. Apogee is apoapsis of an orbit around Earth. People playing KSP speak of apoapsis because Kerbin isn't Earth.
If you think about it, there can't be an ellipse that intersects a circle while also being fully encompassed by the latter. That's to say the periapsis can't be higher than the maneuver altitude that the off-apsis burn takes place as the other guy is suggesting.
On real rockets they add small shelf-stable stage such as the spinny boi Star-48 or the notoriously narcoleptic Fregat, inside fairings between S2 payload interface to actual payload, or let the payload pull itself into the final orbit at a great expense.
Yes, you can keep the S2 burning all the way to Ap and then burn at -45deg at Ap to deform the ellipse back into a circle, or fly a by the book gravity turn trajectory, but that's not the most energy efficient insertion, only what are situationally beneficial when there is land below and acceleration is limited.
You surely know that, but mathematically it is unavoidable to have a 2nd burn at the apoapsis to have an orbit (with a periapsis > the initial launch altitude, minus gravity and atmospheric losses), albeit it may start earlier (while wasting a slight amount of delta-v).
Not necessarily - it is completely dependent on the ascent profile. For example, during the Apollo program, the Saturn V would fly directly into a parking orbit and only relight the S-IVB for the Trans-Lunar Injection burn.
Based on what we saw today, the main chokepoint for Starship might be right in that hot reentry telemetry blind spot. Debugging without logs.
Unless they do find some failure buildup in the logs they did receive, it will be difficult to tell disconnect due to breakup from breakup (long) after disconnect. Gradual signal loss on the receiving side would indicate that it's likely the latter, but I'm not sure a signal loss unrelated to breakup would necessarily be gradual. I'd guess atmospheric properties can change fast at reentry velocity.
That's what pretty much every non-SpaceX rocket does today with very few exceptions.
The big things to fix seem to be
1) The roll rates for starship (which prevented the inflight relighting test)
2) The Booster relights, which didn't have enough lighting to soft land.
Both of those feel like minor problems.
I'm amazed that the propellant transfer demo seems to have worked first time, and of course they managed to get the tihng up there in the first place.
The reusability of the Starship part of the system is a much bigger unknown, but that doesn't seem to be necessary for the next launch.
Wouldn't surprise me if the next try is by the end of April
Not so much a splashdown but a smashdown :-D
Starship will be much more attractive when it will become fully reusable though.
They'll be able to get much larger objects up there without having to piece them together up there. Especially important for habitable objects and factory objects.
Starlink sat deployment, probably. I’m not convinced on the moon lander contract though. Each mission requires the moon lander itself, plus a number of tanker launches to refuel the moon lander. I think it’s something like 8-15 tanker launches.
If each of those tanker launches is an expendable vehicle that’s… probably economically survivable, but definitely not sustainable.
This was still a suborbital flight and they cannot do much of anything that is commercially practical on suborbital flights (like launch satellites, even if they raise their apogee). They appear to have not had good control authority in coast and reentry. They did not do a relight/deorbit burn test that is likely an obstacle to tackle before they can make orbital flights. I assume we'll get some confirmation about these things soon enough, but please, you can be optimistic without being hasty.
If they had flown a slightly steeper ascent and burned for a little longer (possibly a minute if not less), they would have ended in a stable orbit. Not doing that was intentional.
They do not need engine relight capability to reach orbit - plenty of orbital rockets exist that cannot relight their final stage.
So they are at least one more launch away from launching starlinks.
Which then can do without a relight.
> and they can't reliably get into orbit until they demonstrate at least one re-light
And part of testing deorbit/landing capability includes testing that they can relight the engine.
So they could launch the next one with Starlinks (possibly test articles of those as well since no full-size V2 satellites have been laucnhed yet). Get it into orbit and include a deorbit burn/re-entry as part of the flight plan. If the latter part somehow still does not work out ... they still got Starlinks into orbit. And they now have more data to fix it on the next flight. They already have several vehicles lined up for static fires and flight tests.
Why can't they test relight? Also, they are already filing paperwork for IFT-4:
https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=cu...
"Application includes a sub-orbital first stage booster and an orbital second stage"
I don't think SpaceX is interested in having uncontrolled Starship re-entries. It's large enough that (even without a heat shield) debris will very likely make it down to surface.
I’m sure they will have this thing plez dispensing cybetrucks all the way to mars in short order. But I’m also pretty sure that the FAA and whoever SpaceX buys their insurance from are gonna need pretty good assurance that they can control where that thing comes down. Expendable orbital stages are designed and engineered for safe end of life operations and uncontrolled reentery. Starship is not.
no surprise if the next launch has a couple pre-production big starlink birds.
I'm not sure why the ship not immediatly breaking up, but eventually breaking up is proof that they at attitude control - especially against what the live feed showed - rotation.
> If they had attitude control, I think they would have at least stopped the visible rotation at some point before re-entry?
Moreover, I'm guessing the reason they skipped the mock re-entry burn was due to not being able to settle the propellant. Though it's really hard to tell if the turning of the Starship was to rotate which side was getting heating from the sun, or if it was spinning out of (or with less than desired) control.
Tim Todd noticed that the gas thrusters were icing over and then releasing the ice. So it's a reasonable guess that this was part of the issue, but that's leaning even more into speculation territory.
Do we know that? Booster crashed into the water at full speed; landing reignition failed.
Payload able to be delivered to orbit safely and insurable? Ship it. The more you do, the faster you get better.
(And would be very cool marketing and PR, obviously. Not that SpaceX has much need for either of those.)
What SpaceX is doing with Starlink reminds of the situation with early versions of Windows, when, as Bill Gates described, the industry wasn't keen to produce applications for it. So Microsoft started writing Word and Excel in house. Similarly, SpaceX created Starlink which needs lots of launches, and which couldn't exist with previous level of launch prices, but is able to make profits if the prices are as low as SpaceX can provide.
Why? Plenty of boosters re-enter uncontrolled and burn up all the time.
Getting to orbit requires at least one more burn near the apogee of the original orbit to circularize it and ensure the spacecraft doesn't approach the atmosphere again. Starship didn't do the apogee burn they intended to do, so didn't demonstrate this capability.
The Saturn V went direct to Earth orbit without requiring relighting the third stage engine.
Small second stages and spacecrafts can be allowed uncontrolled orbital reentries because they usually burn-up. Starship is too big for that, debris would rain like when Space Shuttle Columbia disintegrated over land. They most likely will need to show engine relight capability to control reentry point before going orbital.
> This requires an engine relight in orbit.
The latter is part of the test at this point of development
It's made of 4mm thick steel sheets, and the FAA disagrees with you.
"Great progress" is a good intermediate.
The Starship program so far has soaked up as much money as SLS, and hasn't even left orbit.
Full-flow staged combustion metholox engines.
Stainless steel construction.
Biggest rocket to have ever flown.
Highest thrust at launch of any rocket by a factor of two or so.
Live streaming of reentry via a space Internet network.
Etc…
Quantity has a quality all of its own.
You should be familiar with this from IT: there’s nothing fundamentally different about the first computer that I’ve ever used to the one I have right now, other than the factor of a million difference in performance!
Why not? With the capability demonstrated today, they can just as easily tweak the ascent profile to end up in a stable orbit outside the atmosphere. Their trajectory was suborbital on this flight on purpose.
There's a bit of nuance to what you are claiming here.
SLS cost $11B to develop, which is estimated to be in the neighborhood of what Starship will cost when development is complete. We don't know how much has been spent so far.
A huge difference is that producing and launching an SLS rocket costs over $2B, while SpaceX is estimating $10M for Starship. Now, I don't trust that $10M number, that's what they aspire for it to cost. To do it they need to be able to reuse the stages dozens of times. It could take a long time to achieve that or they might not make it at all. However, $2B+ per launch is a whole 'nother level of expense.
- More expensive than Starship, or
- Took longer to develop than Starship, or
- Are significantly less ambitious than Starship
(and those are definitely not exclusive ORs)
- Not sure where you're getting the SLS number, the GAO report at https://www.gao.gov/assets/gao-23-105609.pdf claims, "Since 2011, NASA has spent $11.8 billion to develop the initial SLS capability."
- I think the marginal cost is a fair question. The whole party line out of NASA was that this time Moon exploration would be sustainable. If each trip costs > $1B before you even put a payload on the rocket that's a big problem.
SLS use leftover engines from the Shuttle era. Yet it still cost 160 millions. Each. Thrown away after each flight.
Vulcan is a conservative design with no reuse. It also uses BE-4 engine, which costs them nothing to develop.
Space flight is hard and different testing methodologies are no silver bullet. But, I suppose we will know them by their fruits.
It is quite a manipulative word to use.
Its true that SpaceX has gotten federal money contract for landing on the moon to the tune of $2.9B. But the Starship program is going to cost a lot more than that, Musk estimated $10B and has done stock offerings to raise money. And you have to take into account that the federal money has to support 100% of the moon specific parts of development.
So, its true that the feds are helping w/ Starship development but "all" is not accurate.
Then look at expected reusable launch cost and figure out how many HSTs or JWSTs we could have put in orbit for the same cost.
We'll be able to design modular space telescopes that benefit from economies of scale, so that we'll be shipping up the sun shield in separate pieces anyways so if any particular one is lost that's okay we'll have an assembly line to produce more.
Unfolding the heat shield was a relatively minor design issue compared to say the instruments, we just had less ability to actually test it on the ground.
The benefit of starship here is probably being able to massively reduce the expense and risk of future JWST duplicates that don't need to fold. Also in the launch cost, which was $1 billion for Ariane 5 whereas Starship would be in the tens of millions.
[0] https://en.m.wikipedia.org/wiki/Assembly_of_the_Internationa...
Apollo LM: 16 metric tons (landing about 5 tons on the moon)
Apollo CSM: 29 metric tons
The third stage of the Saturn V, called the S-IVB, (which was used for the trans-lunar injection burn) weighed 123 tons - however this was also used to get into the initial orbit.
Starship can launch 150 tons to LEO in reusable mode or ~200 mt when expended. The Saturn V was able to launch 141 tons to LEO. So it should theoretically be possible for Starship to launch an LM+CSM stack with an S-IVB with enough fuel for a trans-lunar injection burn. Then fly the rest of the mission as in Apollo.
Or we can refuel the Starship a few times in LEO using a bunch of re-usable flights and land 100 tons of payload on the lunar surface. The latter is probably cheaper and simpler at this point.
Six... eight... more like twelve... at least 15
Edit: On the other hand tweets from Gwynne suggest that they still need to review the data to see if it was a success.
No humans aboard during Starship launch, transit to and from the moon or re-entry.
(For completeness, humans will do all that other stuff aboard SLS and Orion. Starship literally only ferries them down the moon and back up again)
The first Falcon 9 flight was June 2010.
The first Falcon 9 with astronauts was May 2020.
10 years to get human certified.
In those 10 years Falcon 9 flew 84 times [1].
So I would think Starship needs to fly roughly a similar number of times before it will be human rated. Even if they launch one a month from now on, it will take ~7 years. So I think we're a while away from NASA certifying Starship for human flight, though I wonder in SpaceX would just put their own people on it regardless.
[1] https://www.popularmechanics.com/space/rockets/g32758515/fal...
Not that i think its a big deal... but its important to acknowledge failures so we can learn from them.