Sketches, by Dr. Cameron M. Smith, of Restraint Layers of Pressure Garments Mark I, II, III and IV; Marks I-III are described below. Note reduction of bulk and number of through-fittings between Mark I and Mark III. The Mark IV garment was built in three months in 2015, based on years of experience with earlier models, and will be described later.
Between 2009 and 2013 Dr. Smith and the Pacific Spaceflight team designed and tested a proof-of-concept pressure suit rated to fly to 50,000 feet. After many successful tests, including underwater leak-detection, skydiving stability tests, and altitude chamber tests, we are confident of the essential design, which delivers breathing gas, maintains appropriate pressure, and regulates the pilot’s temperature. You can read a bit about these suits below.
UPDATE: you can see two of our suits, and hear about their design, building, and testing in our 2015 TEDx Portland presentation!
The Mark I suit (the Tsiolkovski) was the first complete build that allowed life support and maintained sufficient pressure through pressurized that lasted over an hour. This suit was used in capsule integration and altitude chamber tests with Copenhagen Suborbitals in Denmark, in summer 2013. The garment was sufficient for many tasks, but suffered from being heavy, complex and somewhat immobilizing at high pressures.
Photo: Dr. Smith in the pressure suit and coverall, taking a break between pressure tests in Copenhagen, August 2013. Photo courtesy of Jev Olsen, Copenhagen Suborbitals.
By February 2014 the Mark II suit (the Gagarin) was fabricated, including refurbished gloves, improved coolant garment features, incorporation of a combined temperature and humidity indicator and, most importantly, convolute, ‘constant volume’ elbows that significantly increase elbow mobility at high suit pressures. The suit’s coverall was also improved and integration with an inflatable life vest was tested.
Photo: Test subject Ben Wilson in a flotation test, Winter 2014.
By September 2014 the Mark III suit (model name “Gagarin +”) was fitted with improved constant-volume elbow segments and smaller communications gear and suit environment monitors, a smaller, low-profile suit pressure gauge and simple C02 monitoring. The suit was flown to over 17,000 in an unpressurized Bell Jet Ranger; biomedical records indicate that Dr. Smith remained in fine health through the 45-minute test, in which his body was ‘fooled’ by the suit to perceive an altitude of only just over 10,000 feet. The Mark III is seen below largely as it was flown on this first test flight.
Photo: Dr. Smith wears the Mark III suit.
Designed following flight tests in 2014, in 2015 we fabricated the Mark IV (model ‘Zaphod’), which was lighter, simpler and less expensive than prior models; it also gave us much better mobility at high suit pressures and used no gas-tight zipper for the entrance, but rather an ‘appendix’ entrance much like that of the venerable ‘Sokol’ suit of Roscosmos the Russian space agency. Though the appendix held some pressure, we were not successful in keeping it gas-tight (likely a materials issue) and retired this model rather quickly — we will revisit the appendix closure in 2017. For the moment, you can get a glimpse at the end of our 2015 TEDx Portland talk!
Photo: Dr. Smith and Mathew Lippincott assist test subject Ben Wilson in the Mark IV ‘Zaphod’ suit in June 2015.
Mark V and VI
Based on lessons of the Mark V, and with new fabrication methods and better materials in hand, we designed the Mark V suit in later 2015 and began building it in mid-2016. It featured yet lighter construction, simpler restraint systems, an improved soft helmet and features specific to flying our balloon in our upcoming high altitude test flights. Rapid development and testing led us to abandon some Mark V features and build a new suit, the Mark VI (model name “Birdie Bowers”), of which not much has been released publicly so far. The suit was first test flown by Ben Wilson in Summer 2016; media agreements limit how much we can say about that at present, but the whole tale will be told!
Photo: Below, Dr. Smith in the Mark VI during a photo shoot for CNN in Spring, 2017.
Rapid design and development followed some fabrication technique breakthroughs in 2016. By May 2017 an entirely new suit was completed and tested on the ground; it again features lower weight, lower cost, simpler manufacturing with fewer seams, an improved flameproof coverall, another iteration of our home-built soft helmets, and an experimental stress-distributing system designed to accommodate the standing position in which we fly our balloon — a unique posture in aviation, one we share with the project Apollo lunar module!
Photo: Dr. Smith in the Mark VII during a photo shoot for CNN in Spring, 2017.