Brooks Range Mountaineering makes an ultralight 4 season tent that weighs under 2 lbs and has a vestibule. That’s right, under 2 lbs. It’s called the A2 Rocket Tent presumably because of the space age material it is made out of.
The first thing you notice about the Rocket Tent is that it has a metallic interior like a space blanket, and the skin of the tent is basically that, except it’s aluminumized cuben fiber. The tent is single-walled, includes a nearly transparent floor and has a solid zippered front door.
Weight Reduction Strategy
Structurally, the Rocket can be pitched with 2 hiking poles, set to 115 cm, and a 300 cm avalanche probe, which runs along the top of the tent in an enclosed cloth tube. The use of existing equipment like hiking poles and an avalanche probe is quite nice, and certainly the hallmark of an ultralight shelter design.
Minus poles and probe, the base tent weighs just 1 lb 6 oz. Brooks-Range also provides an optional summer pole set, including 2 side poles (5.4 oz total) and a 300 cm top pole (5.4 oz) if you don’t use adjustable poles or carry an avalanche probe all the time. These are included with the A2 “summer” model of the Rocket that I tested.
Although the Rocket virtually stands by itself with just the 3 poles as supports, you do need to stake it out to anchor it against the wind. In all, the tent requires ten anchors, three on each side, one facing into the wind, one for the vestibule, and two to pull the top of the sides out to create more headroom inside.
The eight ground level tie outs are extra long canvas straps that can be anchored using skis, axes, or pickets, or simply guyed out using dead men.
For this test and review, I used everything from an ice axe and snow shoes to plastic grocery sacks as tent anchors! Lovely stuff.
Though rated by the manufacturer for two people, the interior space in the Rocket feels more cramped than the floor plan dimensions would suggest (48″W x 87″L x 38″H.) This is because the side walls slope inward to the center ridge, starting at the floor seams and not higher up in the tent body. This can be mitigated somewhat by using the upper tie outs on the outside of the tent to create more interior space, but the available head room is still compromised by the A-frame shape of the tent structure.
The floor plan is pentagram shaped, with a rectangular area on the door side of the tent that is 64″ long, and a triangular area at the rear (23″ deep), where the ridgeline of the tent descends sharply and there is virtually no headroom. For maximum comfort, sleepers should orient their heads at the vestibule end of the tent where the ventilation and headroom are more tolerable.
On the plus side, the built-in vestibule is smallish (7 square feet), but an absolute luxury on a mountaineering tent, and imposes virtually no additional weight penalty or cost – which is unheard of, on tents in this category. While the vestibule can be used to store gear in, especially snow-covered gear, it can also be further expanded by digging a pit under it for more storage capacity, as shown in the top two photos, above.
To reduce condensation, the Rocket has four vents, three located to the rear of the inner compartment that perforate the outer skin and one above the front door, under the tent’s front peak. All of the vents are lined with mesh, and the ones in the back have external beaks covering them that can be zippered closed from the inside.
It would be nice if the vents were much larger and that the fabric covering the outside vents included a bendable wire in the rim to ensure that the vents stay open from the outside. Black Diamond provides this in the FirstLight 4 season tent, which is the nearest competitor to the Rocket, and it really helps control ventilation and rain splatter.
The only other way to increase ventilation in the Rocket is to sleep with the front door open and/or the vestibule sides rolled back. There are snaps on the tent sides to hold the rolled back fabric in place, but doing so will depend on exterior weather conditions.
In addition, to the features described, there are two additional holes in the sides of the tent which enable climber tie-outs in extreme conditions, such as on a ledge or in very bad weather.
I tested the Rocket in winter conditions in the White Mountains in New Hampshire, camping on a 50″ base of snow. Temperatures were in the single digits with winds gusting to 40 mph.
The biggest issue I had with the Rocket was interior condensation, even though I was sleeping alone. While sleeping in the aluminumized compartment is perceptibly warmer, cross ventilation in this tent is very poor. So, when I awoke the next morning, there were water droplets on my sleeping bag, the floor was wet, and frozen condensation lined the tent walls. This occurred despite the fact that I slept with the front door and vestibule wide open all night.
Sleeping at higher altitudes in colder, drier environs may mitigate internal humidity somewhat, but I would expect that condensation will be even worse with two people in the tent, particularly since their sleeping bags will be in direct contact with the inner sides of the tent.
Other than that, the tent held up admirably. The fabric was fairly quiet and not rustly, even with snow fall at night, and the steep tent walls shed the snow without issue. The next morning, I did notice that the tent walls had relaxed somewhat overnight, losing the taughtness of the previous evening’s pitch, but not in any way that affected wind resistance or the stability of my snow stakes and anchors.
Set up and tear down of the tent is actually quite easy, although I didn’t have to do this in high wind. However, repacking the tent into the tiny stuff stack provided by BRM is nearly impossible, indoors or out, and you’ll want to use a slightly larger stuff sack in the field. Despite this, the tent compresses quite nicely in a mountaineering backpack and is roughly equivalent in size to a compressed down summit parka, making it an attractive shelter option from a compressibility standpoint.
Range of Use
I wouldn’t recommend that you buy the Rocket as a base camp tent or even for ultralight winter backpacking. I feel that its condensation performance really limits its desirability as a shelter, particularly for multi-day treks where you may be willing to tolerate carrying a bit more weight, for more comfort and far less expense. Design wise, it’s very cleverly done, but probably exceeds most people’s needs for sub-alpine climbing, backpacking, or ski mountaineering, particularly in the eastern US.
Instead, I view the Rocket as a step up from a bivy sack in comfort, ideally designed for a 2 person climbing or mountaineering team, who want a very lightweight shelter for a fast and light summit attempt. For a 2 person team, this tent makes a lot of sense when compared to an 18-22 oz mountaineering bivy for one person, both in terms of weight and compressibility. While I wasn’t able to quantify the temperature benefits of the aluminumized cuben fiber, I suspect it would be possible to reduce the total insulation weight required by 2 occupants to stay warm (enough) overnight, before an alpine start, or to spend an extra night out in poor conditions.
Disclosure: Brooks-Range Mountaineering loaned Sectionhiker.com a Rocket Tent for this review