Is The Uni-ball Power Tank Better than the Fisher Space Pen?

OK, credit where it’s due: The Fisher Space Pen was one of those brilliant little byproducts of the American space program like Tang and cordless drills. With its pressurized ink cartridge that could write on any surface from any angle, it did for ballpoint pens what the iPhone did for cell phones.

But that was more than 40 years ago.

The Fisher Space Pen is no longer the only ballpoint capable of functioning under less-than-ideal conditions. A number of other pens also can make that claim, chief among them the handy Uni-ball Power Tank RT that writes a neat, clean .4mm line. 

Uni SN 220 Powertank Blue
Uni Power Tank Ballpoint Pen

So when it comes to the Uni-ball Power Tank vs The Fisher Space Pen, is it a better choice than Fisher? We think so.

Check Price and Reviews on Amazon

 1. Fisher Space Pens Background Info

First, a little background for those who aren’t familiar with Fisher Space Pens.

NASA was trying to find a reliable writing instrument for astronauts in the early ’60s. Ballpoint pens would not work because they relied on gravity to feed ink to the ball and then onto paper. Pencils were encased in wood, which was flammable, a dangerous potential in space. NASA tried buying mechanical pencils but ended up paying $142 each, which did not sit well with the public.

Paul Fisher already had succeeded in inventing a universal ballpoint pen refill that fits most of the popular brands than on the market. He went to work on a pen that would perform in the unique conditions of space. That meant it had to function by some means other than gravity and had to withstand extremes of heat and cold.

His company reportedly spent $1 million on research, and the result was the Space Pen. By adding gas pressure to the cartridge and using low-viscosity ink, Fisher created a pen that could write underwater, in zero gravity, and in temperature ranges from -45C to 204C.

NASA scientists put the pens through testing and, in 1967, agreed to buy 100 of them for the Apollo space mission.

With that purchase, Fisher pens became famous. He began selling them to the public, and they were immensely popular. The pens were the first product ever sold from space – via QVC – and became the subject of a Seinfeld episode. Although Fisher died in 2006, his company continues and offers a whole range of space pens.

2. Writing Underwater with a Fisher Space Pen

And no doubt about it, they’re neat pens. Take a look at this video of a reviewer using it to write underwater.

3. Uni Power Tank Features & Reviews

But the Power Tank by Uni-ball also has a pressurized ink cartridge and is capable of writing on wet or dry surfaces and from any angle, including upside down. It, too, is resistant to temperature extremes and performs well under adverse conditions. This pen, as well, uses low-viscosity Uni Super Ink (which is waterproof and fade- and tamper-resistant.) And, while Uni-ball makes no claim the pens can write underwater, there doesn’t seem to be any reason they shouldn’t.

OfficeSupplyGeek wrote an outstanding review of the Power Tank last year. He found that the pen wrote equally well right-side up, upside down and at low temperatures. He even conducted an experiment that involved putting the pen in a tube of water, freezing it and then seeing how well it would write. Frozen, the pen managed to write about as well as it had at room temperature.

Alex also wrote for us a fantastic in-depth review of the Uniball Power Tank which is well worth checking out. and Kim asks the question The Uni Power Tank Ballpoint Pen Does It Live up to the Hype?

Reviewers on also give the pen high marks for performance, including this one:

These are great all-weather pens. I use them at home and work, but I initially got them for geocaching. I needed something that could withstand cold temperatures as well as wet conditions. The old “space” pens came to mind, but they had lots of problems and were clunky. These seemed to have fixed all those problems. My pen works when other pens, and even pencils, have failed. Oh, yeah, they do write upside down and for long periods when writing on a pad against a wall (i.e., vertically).

Of course, the Power Tanks don’t have sleek metal bodies and aren’t precision-machined like the Fishers. Instead, the retractable pens are made of tough plastic, have comfortable rubber grips and are translucent so you can gauge when you need a refill.

4. Conclusion

But you want to know the main difference in the pens? Cost.

Uni Pens Lower Price

You’ll spend almost £20 for a Fisher Space Pen. A Power Tank will cost you less than £2.

There may be something to owning a pen with the storied history of the Fisher. And the pens do look good, especially the original astronaut pen and the bullet pen, which fits as neatly into a pants pocket as any pen could. Is that worth the extra money, though?

Not really, especially given how often people lose their pens. Most of us just want a good, reliable pen that fits well in our hands and will do its job even in difficult conditions. If it’s got a little style, all the better. The Power Tank does everything we want it to do, for about a tenth of the price.

You just can’t beat that.

What do you think, readers?

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Tony Bridges

As a seasoned journalist and freelance writer, I've spent over three decades telling stories and exploring the world through the written word. With a passion for writing instruments, I found my niche at The Pen Vibe, a blog that shares our collective fascination with pens, pencils, and other tools that have shaped the art of writing.

8 thoughts on “Is The Uni-ball Power Tank Better than the Fisher Space Pen?”

  1. You just cannot replace the feel of a Fisher AG7. The weight, the metal, the incredible mechanism. Sure, the UniBall may do the same thing, but the Fisher isn’t just a pen. It’s an experience. It’s a piece of functional art. For me it’s well worth the money.

    • Hi, James, I use them both I think the Space pen may be a slightly smoother writer than the Power Tank but there is not a lot in it. If you are looking for a cheap pressurised pen then Power Tank is excellent value and the best out there.

  2. I love my Power Tanks. I’ve been using them for some time since researching alternatives to the Fisher Space Pen (exactly because of the cost & frequency of losing pens to colleagues etc). I originally wanted a pen that I could use for sudoku and crossword puzzles in bed lying on my back – they are also great for writing while leaning against walls or on shiny paper or paper that might have ggot a bit damp / greasy. I have Power Tanks in my handbag, my work bag, my car and on my desk… and a box of refills in my drawer! Just about everyone who borrows one comments on how nicely they write – at all angles.

    I have tested writing in a shallow bowl of water – they work 🙂

  3. Looks like I also need to do an underwater test of the Power Tank. I bought one of these a while back and have been meaning to do a comparison against the Fisher Space Pen, but just haven’t gotten around to it yet. I’ll let you know once I have a video up for the Power Tank.

    Just an FYI…I’ve been using the Power Tank for a while and I do like it quite a bit. =)

    • Debi, I’d love to see the underwater test. I’ve heard of people using the Power Tank to write in rainy conditions and on wet paper, but never of anyone doing it underwater. Seems like it should work, but we’ll have to see. If the grip was a little thicker, I might use it as my daily go-to pen…as it is, though, it’s on the list of potential favourites. Please keep us posted.


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