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Ozan Bellik Profile picture
Ozan Bellik
@BellikOzan
Software engineer and aerospace nerd. Here mostly for space conversations. https://t.co/f3KuY8BDLV https://t.co/bIdsWczD8n
Sep 3, 2023 • 6 tweets • 2 min read

I really don't expect anyone to look at whatever ULA may or may not be cooking for the far future and say "Woah, ULA is doing *that*!? Time to change our plans and do something totally different."

Sure, they don't need to share, but I don't buy the corporate counter-intel line.
Aug 21, 2023 • 10 tweets • 2 min read
Did we answer your questions on Starship hot staging?

@FullOfStarships @NilsDohrmann Dev amortization
Jul 29, 2023 • 13 tweets • 3 min read
Yes!! This is the data I was looking for, and the reason I've been waiting for this launch.

Probably safe to assume they got Jupiter 3 as close as they could to GEO w/ reasonable margin. Now we can get an estimate of the current usable performance of this FH config.

🧵 One thing that's worth noting is that they did the third burn at a bit under 28400km altitude, instead of waiting to get all the way to apogee (which would have yielded a more efficient circularization + inclination correction burn).

If my math is right, this caused 2/
Jul 18, 2023 • 15 tweets • 4 min read
"But it can't launch Orion!"

FH could've launched Orion to LEO, easily. (Not that Orion is a good way to go.)

"But multiple launches!"

Yeah, we were & are going to do that anyway. Even Constellation used multiple launches, let alone Artemis. @Robotbeat @brickmack By contrast, Orion in lunar config is 26.5 + the 7t LAS (which should the equivalent of somewhere in the neighborhood of 1t in LEO req).

And the rendezvous orbit won't necessarily be 200km circular at ~28 deg.

So ~5t short maxed out and might still need to dip into Orion prop.
May 19, 2023 • 27 tweets • 4 min read
Pleasantly surprised by the 3.4B price for Blue's lander contract (compare to 2.8B for SpaceX's, primary contract which wasn't for the higher spec sustaining dev).

Also pleasantly surprised by the architecture, which seems to be a lot more Blue. 20t payload to the surface 1/ w/ full reuse; 30t one-way.

This is going to mean substantial TLI mass, with refilling in Earth and lunar orbit.

They really took Starship's win to heart.

Really curious to see how many NG flights it'll be...
Mar 15, 2023 • 38 tweets • 6 min read
Gonna read and comment 🧵 - Figure 1 is highly misleading. Burns, longest coast, and time to sep do not materially impact whether a trajectory is low or high energy.
Also, GSO direct inject is not for USG only. There's a Viasat launch coming up in a month.

1/
Mar 15, 2023 • 4 tweets • 1 min read
No.

Unless he means that Vulcan can launch more to LEO that FH can directly inject into GSO. *than
Mar 15, 2023 • 22 tweets • 5 min read
An excellent thread @octoberskyshow Securing funding to tie to uncancellable projects becomes the focus and results that fall far short of what's possible become the norm.
Mar 2, 2023 • 16 tweets • 3 min read
In my recent thread on Starship depots () I said that a stretched depot would imply long term storage. Here's why I was wrong. 🧵 I'd been assuming that the main tanks would be used for depot storage. @SpaceDevClub and @OrenTirosh argued for the likelihood of separate internal tanks for depot storage in the cargo area.

1/
Feb 28, 2023 • 22 tweets • 5 min read
I see a lot of doubt and uncertainty around SpaceX orbital refilling plans (once they get it working). Esp around the unknowns of boil off rates, capacity, operational tempo, insulation, etc.

I want to provide a bit of context here to help interpret what we see 1/ First, regarding the question of whether the depot would be filled just in time for a particular mission or maintained partially filled in between missions:
the main reason to fill just for a particular mission is to avoid boil off, but if you're trying your best to avoid 2/
Jan 30, 2023 • 5 tweets • 1 min read
You know how if SpaceX says if you expend the whole Starship stack it can get 250t to orbit?

Well, if you boostback SuperHeavy to launch site, and use a much smaller (~400t prop) expendable second stage w/ a single *sea level* Raptor (no vac engines), you can sill get ~90t... You might ask why you'd want to do this.

Well, if you've got SH reuse sorted out but not Starship reuse (or you want to launch very bulky things that won't fit in the regular Starship cargo bay), here's your semi-reusable Starstack w/ minimal launch cost.

If you can get ~50 1/
Jan 14, 2023 • 18 tweets • 4 min read
Still seeing a lot of confusion about launch pricing. Let's talk about this again, w/ a hypothetical RLV to highlight the fixed cost issue.🧵 Let's say I have an awesome superheavy RLV that costs $1M in propellant per launch, $0.5M in refurb, cost $150M to build and can fly 300 times, so $0.5M in amortized build costs, and I manage to get range and ops costs down to $1M as well, for a total marginal cost of $3M.

1/
Aug 31, 2022 • 19 tweets • 7 min read
@ErickHe369 Gladly.
A. This is what it is designed for, and it's the only spacecraft w/ that role in mind that's currently in serious dev.
B. The SX team has proven themselves to be fast, capable, and determined.
C. Most of the challenges associated with using it in that role are those 1/ @ErickHe369 that NASA expects them to solve by around the middle of this decade (propulsive landing, refueling, and atmospheric EDL (for high cadence tanking)).
(Challenges unique to Starship, that is; not Mars challenges in general.)
D. The expected dev costs are far cheaper than the 2/
Feb 11, 2022 • 27 tweets • 5 min read
Could only catch the beginning of the Starship presentation yesterday. Watching now.
Thoughts below 🧵 - 30 min refill of SH is amazing; they're still aiming for as low as 1hr turnaround! (18m)
- 10-15% of LEO mass to surface of Mars sounds like relatively high transit speed (not dominated by slow cargo; maybe for a mix of cargo & crew?) (19m)
- still aiming for full autarky

1/
Feb 8, 2022 • 7 tweets • 2 min read
I've gotten a number of responses to this saying it's just a solid rocket motor, so let's talk about the components that actually have to come together for this. 🧵 The Mars Sample Return mission involves two big parts. The first part takes the samples to Mars orbit, and the second takes the samples from Mars orbit and returns them to Earth. Both are quite complex but independently launched, so for this thread, I'll leave out the 1/