SpaceX Says Starship Can Beat “Plasma Blackout” With Starlink Antennas
SpaceX has asked the FCC to allow Starship and its super heavy booster to communicate with Starlink during the rocket’s first attempt at orbital launch.
SpaceX’s Special Temporary Authority (STA) application filed on June 28 contains a number of surprising details about the company’s plans to expand the experimental use of its Starlink satellite constellation for in-flight missile communications. These efforts were first made public in April 2021 when a separate FCC application revealed plans to test Starlink on a Starship prototype. Starship serial number 15 (now known as Ship 15 or S15).
This particular prototype was the first of its kind that successfully took off and landed in one piece on May 5th. Nothing is known about whether Starlink was actually used or how the Starship’s lone bowl fared during the 10-kilometer flight test, but SpaceX’s plans to recombine both Star programs offer some new lines to read.
SpaceX has applied for FCC clearance to fly Starlink terminals on the Super Heavy and Starship vehicles during the orbital launch demonstration. The desired start date is August 1st, ie no start in July if SpaceX wants to fly with Starlink on board. Https://t.co/1NiKWHJ9sx
– Michael Baylor (@nextspaceflight) June 29, 2021
Especially when compared to its first Starlink Starship STA application, SpaceX doesn’t split hairs in the “narrative” attached to its latest request. In particular, SpaceX is repeatedly discussing Starlink’s potential to dramatically improve the state of the art in routine telemetry and communications from spacecraft and launch vehicles.
“SpaceX intends to demonstrate high data rate communication with Starship and the Super Heavy Booster on the ground at the Starbase, TX launch pad during launch, during booster recovery, in flight, and during reentry. Starlink can provide unprecedented amounts of telemetry and enable communications during atmospheric re-entry when ionized plasma around the spacecraft inhibits conventional telemetry frequencies. These tests will demonstrate Starlink’s ability to improve the efficiency and safety of future orbital space missions.“
SpaceX – June 28, 2021
In short, in the two months since SpaceX first applied for permission to “operate a single user terminal … during flight tests,” the company appears to have become extremely optimistic about Starlink’s potential as a missile communications solution. The logical conclusion is that Starlink performed well on the ground and in flight during its tests aboard the Starship S15 – possibly even exceeding SpaceX’s own expectations. At the same time, SpaceX is in the process of expanding Starlink’s aviation communications certification efforts and has ramped up tests on airplanes, ships and road vehicles in general.
In fact, the same attributes that allow Starlink to blast traditional consumer satellite communications solutions could, in theory at least, make Starlink a boon for launch vehicle communications. This is especially true for the test flights of experimental launch vehicles like Starship, where failure is an inevitable part of the development process. However, these startup errors are only beneficial in that they expand the knowledge base and enable lessons to be learned.
The Falcon 9’s main telemetry antenna is visible on the intermediate stage of the booster. (Richard Angle / BocaChicaGal)
So data is essential and the more data that is gained from test flights, the better. Even with modern missiles, state-of-the-art telemetry usually requires a maximum bandwidth on the order of a few hundred to a few thousand kilobits per second, which often requires software and compression gymnastics and inconvenient triage to ensure that all of the telemetry required continues to flow.
If Starlink could expand that bandwidth from a few megabits per second (Mbit / s) to tens or even hundreds of Mbit / s, SpaceX could extract unprecedented high-resolution telemetry from Starship and Super Heavy and an abundance of during their first orbital test flight Leave data for probable failure analysis after the flight.
A spaceship enters the Martian atmosphere in this artist’s rendering. (SpaceX)
Perhaps most surprisingly, SpaceX’s claim that Starlink antennas could allow Starship to maintain a strong communications link throughout orbital re-entry. Traditionally, all re-entry spaceships produce an overheated plasma envelope as they speed into the Earth’s upper atmosphere. This plasma effectively blocks most radio waves, resulting in an inevitable communication loss of several minutes for each re-entering spacecraft.
The next big technology revolution is at SN20. These ships will be able to orbit with a heat shield and a step separation system. The likelihood of success in advancement is high.
However, SN20 + vehicles will likely take many attempts in flight to survive the Mach 25 entry heating and landing intact.
– Elon Musk (@elonmusk) March 30, 2021
If Starlink can somehow enable SpaceX to break through this “plasma barrier,” it would give the company an unprecedented ability that is invaluable in the process of perfecting spacecraft reentry, descent, and landing – a process that Musk expected with several unsuccessful attempts. According to SpaceX’s FCC filing, Starship’s first orbital launch and re-entry attempt could occur as early as August 2021.