reflections of a pragmatic optimist, lover of freedom

Author: Troy Stephens (Page 1 of 115)

A Spectacular Starship Test

Though it ended in another “rapid, unscheduled disassembly” instead of the successful landing we’d hoped for, yesterday’s test-launch of the Starship SN9 prototype was a spectacular sight and will doubtless yield valuable data and help inform the next attempts and further evolution of SpaceX’s prototypes.

Like SN8, SN9 reached its target altitude (10km this time) with smooth stability. The controlled free-fall went remarkably well, as it did for SN8, which is a very encouraging result given the importance of this means of re-entry to the design. An interesting difference vs. the SN8 test was a very visible overshoot during the rotation back to vertical, which SN9 attempted unsuccessfully to correct. An astute observer pointed out to me that SN9 had only one engine firing at the time, whereas reviewing the SN8 test flight’s landing you can see two Raptors firing during the landing attempt (until one of them started to burn out with a bright green flame, at least). This leads one to wonder whether the failure was at least partly a matter of not having sufficient thrust (and the stability of a pair of pivoting thrust sources vs. just one) to correct the overshoot past vertical once it happened. But noting that SN8 rotated to vertical more slowly without overshooting and having to correct, it also seems like maybe a gentler approach to the rotation maneuver could have avoided the problem. I therefore wonder if control software or the feedback loop of sensors that informs it could have been partly at fault. Maybe the software that controls the maneuver, adaptive as it is designed to be, has a certain degree of hard-to-avoid reliance that the engines will successfully ignite and start providing thrust on command, and is limited (both logically and physically, with only one gimbaled rocket motor firing) in its ability to cope with failure of one engine to relight. I’m very curious about what actually happened and am looking forward to SpaceX’s findings and resultant changes to the next prototypes.

Here’s SpaceX’s livestream footage from yesterday:

Here’s SN8’s test-launch and landing attempt for comparison:

And here’s an illuminating side-by-side comparison and SN9 crash analysis from Terran Space Academy:

SN9 Launch Today?

I’m tempering my excitement with the knowledge that further delays are possible, but signs are currently pointing to a Starship SN9 12.5km hop attempt today. A successful ascent, controlled free-fall, and vertical landing will be a huge milestone for SpaceX’s Starship program and our prospects of going places in these magnificent, ambitious vehicles.

Check LabPadre’s Nerdle Cam or the NASASpaceflight channel for the livestream. Barring a @SpaceX announcement, the time of the test flight may remain a mystery as usual. It’s been a magnificent sight to see SN9 and SN10 standing side-by-side at the launch site for the past few days. With visuals like this, it’s not hard to imagine a sci-fi future made real where we have fleets of Starships in active service.

The huge crane that’s used to put them in place is a pretty awesome sight too:

Tune in to the Nerdle Cam livestream for more!

In related news, this 4-minute video from Terran Space Academy presents the significance of SpaceX’s achievements to date and the Starship program beautifully:

(For more from this great channel, check out Starship: The Next Generation.)

Last but not least, an exciting announcement from SpaceX regarding the next phase in its crewed Dragon program:

Today, it was announced SpaceX is targeting no earlier than the fourth quarter of this year for Falcon 9’s launch of Inspiration4 – the world’s first all-commercial astronaut mission to orbit – from historic Launch Complex 39A at NASA’s Kennedy Space Center in Florida. Jared Isaacman, founder and CEO of Shift4 Payments, is donating the three seats alongside him aboard Dragon to individuals from the general public who will be announced in the weeks ahead. Learn more on how to potentially join this historic journey to space by visiting Inspiration4.com.

The Inspiration4 crew will receive commercial astronaut training by SpaceX on the Falcon 9 launch vehicle and Dragon spacecraft, orbital mechanics, operating in microgravity, zero gravity, and other forms of stress testing. They will go through emergency preparedness training, spacesuit and spacecraft ingress and egress exercises, as well as partial and full mission simulations.

This multi-day journey, orbiting Earth every 90 minutes along a customized flight path, will be carefully monitored at every step by SpaceX mission control. Upon conclusion of the mission, Dragon will reenter Earth’s atmosphere for a soft water landing off the coast of Florida.

What an amazing time to be alive.

The Loss of Columbia

Eighteen years ago today, in the second and last major catastrophe of the Space Shuttle program, we lost Columbia and her crew. Tragically, as with Challenger, this loss might have been avoidable had we found a better way to secure the insulating foam around the external tank that ended up breaking loose, damaging Columbia’s left wing, and leaving the shuttle’s airframe vulnerable to being pierced by hot gases on re-entry. On the other hand, judging such things foreseeable is often all too easy with the benefit of hindsight. Sometimes in the dangerous endeavor of spaceflight, however diligently we may try to anticipate all scenarios and control all the variables, unexpected stuff happens and there’s not much we can honestly do but chalk our failures up to bad luck. There is danger in this grand adventure. We know it. And we go anyway.

Columbia had the proud distinction of being the first shuttle to fly. I remember learning about and watching that first flight from my 4th grade classroom in Los Angeles, and somewhere I probably still have the excited pencil scrawlings of my 4th grade self celebrating this human accomplishment and imagining myself one day as an astronaut taking the same journey to space.

Bill Whittle’s 2003 essay, Courage, written in the wake of the loss of Columbia, captures the magic and tragedy of it all in soaring poetry I have not seen surpassed anywhere. I can’t recommend it highly enough.

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