
Latest issue
Five Layers, One Million SPF: The Thermal Engineering That Made Webb Possible
7/29/2026
The number that keeps engineers up at night isn't the 344 single-point failures Webb carried into space — though that's alarming enough. It's the temperature differential the sunshield has to maintain: roughly 585 degrees Fahrenheit between the sun-facing side and the cold side w…
Recent posts
The hardest moment in a lunar landing has nothing to do with the final touchdown. It happens roughly 10 kilometers up, when the lander transitions from a high-energy descent burn t…
The capsule hit the atmosphere at 24,581 miles per hour — roughly 24 times the speed of a bullet. The heat shield surface climbed to nearly 5,000 degrees Fahrenheit, roughly half t…
Sixteen miles in 37 hours. That's what ERNEST, NASA's new rover prototype, just completed in the California desert — more than ten times the speed at which Perseverance can navigat…
The rocket made the decision before any engineer did. Webb's primary mirror spans 6.5 metres across — a gold-coated beryllium structure that needed to be the largest mirror ever de…
There's a specific kind of engineering courage required to put one engine between your crew and a fatal outcome. No backup. No second chance. One combustion chamber, one turbopump,…
The hardest part of returning from the Moon isn't the heat. It's that the thing protecting you from the heat also has to hold the spacecraft together while it's being heated. That…
The intuitive answer is wrong. When people ask why Mars rovers use wheels instead of legs, the usual response is something like "wheels are simpler" or "legs break more easily." Bo…
There's a number that stops engineers cold when they first encounter it: one kilowatt. That's roughly what the James Webb Space Telescope uses to run everything — four science inst…
There's a moment in the Artemis II commander's post-mission interview that cuts right to the engineering logic of the whole program. Reid Wiseman was asked when he knew the mission…
Liquid hydrogen is the most efficient chemical rocket propellant available. It's also, at -253°C, one of the coldest substances you'll ever try to store on a spacecraft — and the M…
A structure designed to survive launch is, almost by definition, poorly suited for landing. Launch loads are axial — the vehicle is a column under compression, and you want stiffne…
Pick your propellant, and you've just made choices about your tanks, your thermal management, your launch window flexibility, your ground support infrastructure, and your mass budg…
The six-day clock on Artemis II isn't a scheduling choice. It's a hard constraint written in tank volume. During NASA's pre-mission briefings, officials were direct about it: "thos…
Perseverance travels a few hundred meters on a good day. Not because the wheels can't spin faster — because every meter requires a conversation with Earth that takes, at minimum, e…
For most of its life on Mars, Perseverance navigated the way sailors did before GPS: dead reckoning. Take a picture, identify a rock, calculate how far you've moved. Repeat. It wor…
The solar cells powering satellites today cost roughly 1,000 times more per watt than the panels on your roof. That's not a rounding error — it's the fundamental constraint that ha…
The Artemis II coverage has been full of justified excitement about O2O — the Orion Artemis II Optical Communications System that's been beaming 4K video from lunar distance, cappi…
There's a constraint that governs every Mars landing site decision that rarely makes it into the press release: the entry corridor. The range of permissible flight path angles for…
There's a number that haunts every thermal protection system engineer: 2,900 degrees Fahrenheit. That's roughly the surface temperature a capsule's heat shield faces during a high-…


















